WordPress Plugin autoupdate API integration code example

The first part of the code consist of few constants definition which are being used later within the code.

//the url where the WooCommerce Software License plugin is being installed
define('SL_APP_API_URL',      'http://YourDomainWhereSoftwareManagement.com/index.php');

//the Software Unique ID as defined within product admin page
define('SL_PRODUCT_ID',           'APTO');

//A code variable constant is required, which is the user application code version. This will be used by API to compare against the new version on shop server.
define('SL_VERSION', '1.4.2');

$protocol = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off' || $_SERVER['SERVER_PORT'] == 443) ? "https://" : "http://";
define('SL_INSTANCE',             str_replace($protocol, "", get_bloginfo('wpurl')));

A plugin auto-update code can be inserted within the plugin, here is an example:

class WOOSL_CodeAutoUpdate
        {

            // URL to check for updates, this is where the index.php script goes

            public $api_url;

            private $slug;
            public $plugin;

            public $current_version;
            
            private $API_VERSION;

            public

            function __construct($api_url, $slug, $plugin)
            {
                $this->api_url = $api_url;
                $this->slug = $slug;
                $this->plugin = $plugin;
                
                //use laets available API 
                $this->API_VERSION =   1.1;
                
            }

            public function check_for_plugin_update($checked_data)
                {
                    if (empty($checked_data->response) ) return $checked_data;
                    $request_string = $this->prepare_request('plugin_update');
                    if ($request_string === FALSE) return $checked_data;

                    // Start checking for an update

                    $request_uri = $this->api_url . '?' . http_build_query($request_string, '', '&');
                    $data = wp_remote_get($request_uri);
                    if (is_wp_error($data) || $data['response']['code'] != 200) return $checked_data;
                    $response_block = json_decode($data['body']);
                    if (!is_array($response_block) || count($response_block) < 1)
                    {
                        return $checked_data;
                    }

                    // retrieve the last message within the $response_block

                    $response_block = $response_block[count($response_block) - 1];
                    $response = isset($response_block->message) ? $response_block->message : '';
                    if (is_object($response) && !empty($response)) // Feed the update data into WP updater
                    {

                        $response  =   $this->postprocess_response( $response );
                             
                        $checked_data->response[$this->plugin] = $response;
                    }

                    return $checked_data;
                }

            public function plugins_api_call($def, $action, $args)
                {
                    if (!is_object($args) || !isset($args->slug) || $args->slug != $this->slug) return $def;

                    $request_string = $this->prepare_request($action, $args);
                    if ($request_string === FALSE) return new WP_Error('plugins_api_failed', __('An error occour when try to identify the pluguin.', 'apto') . '&lt;/p> &lt;p>&lt;a href=&quot;?&quot; onclick=&quot;document.location.reload(); return false;&quot;>' . __('Try again', 'apto') . '&lt;/a>');;
                    $request_uri = $this->api_url . '?' . http_build_query($request_string, '', '&');
                    $data = wp_remote_get($request_uri);
                    if (is_wp_error($data) || $data['response']['code'] != 200) return new WP_Error('plugins_api_failed', __('An Unexpected HTTP Error occurred during the API request.', 'apto') . '&lt;/p> &lt;p>&lt;a href=&quot;?&quot; onclick=&quot;document.location.reload(); return false;&quot;>' . __('Try again', 'apto') . '&lt;/a>', $data->get_error_message());
                    $response_block = json_decode($data['body']);

                    // retrieve the last message within the $response_block

                    $response_block = $response_block[count($response_block) - 1];
                    $response = $response_block->message;
                    if (is_object($response) && !empty($response)) // Feed the update data into WP updater
                    {

                        $response  =   $this->postprocess_response( $response );
                             
                        return $response;
                    }
                }

            public function prepare_request($action, $args = array())
            {
                global $wp_version;
                return array(
                    'woo_sl_action'         => $action,
                    'version'               => SL_VERSION,
                    'product_unique_id'     => SL_PRODUCT_ID,
                    'licence_key'           => $license_key,
                    'domain'                => SL_INSTANCE,
                    'wp-version'            => $wp_version,
                    
                    'api_version'           => $this->API_VERSION
                );
            }
            
            private function postprocess_response( $response )
                 {
                     //include slug and plugin data
                     $response->slug    =   $this->slug;
                     $response->plugin  =   $this->plugin;
                     
                     //if sections are being set
                     if ( isset ( $response->sections ) )
                        $response->sections = (array)$response->sections;
                     
                     //if banners are being set
                     if ( isset ( $response->banners ) )
                        $response->banners = (array)$response->banners;
                       
                     //if icons being set, convert to array
                     if ( isset ( $response->icons ) )
                        $response->icons    =   (array)$response->icons;
                     
                     return $response;
                     
                 }
        }

        function WOOSL_run_updater()
            {
                $wp_plugin_auto_update = new WOOSL_CodeAutoUpdate(SL_APP_API_URL, 'plugin-slug', 'plugin-folder/plugin-filename.php');

                // Take over the update check

                add_filter('pre_set_site_transient_update_plugins', array(
                    $wp_plugin_auto_update,
                    'check_for_plugin_update'
                ));

                // Take over the Plugin info screen

                add_filter('plugins_api', array(
                    $wp_plugin_auto_update,
                    'plugins_api_call'
                ) , 10, 3);
            }

        add_action('after_setup_theme', 'WOOSL_run_updater');